int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb), void *from, int length, int transhdrlen, int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6, struct rt6_info *rt, unsigned int flags, int dontfrag) { struct inet_sock *inet = inet_sk(sk); struct ipv6_pinfo *np = inet6_sk(sk); int exthdrlen; int err; if (flags&MSG_PROBE) return 0; if (skb_queue_empty(&sk->sk_write_queue)) { /* * setup for corking */ err = ip6_setup_cork(sk, &inet->cork, &np->cork, hlimit, tclass, opt, rt, fl6); if (err) return err; exthdrlen = (opt ? opt->opt_flen : 0); length += exthdrlen; transhdrlen += exthdrlen; } else { fl6 = &inet->cork.fl.u.ip6; transhdrlen = 0; } return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base, &np->cork, sk_page_frag(sk), getfrag, from, length, transhdrlen, flags, dontfrag); }
static int alloc_sg(struct sock *sk, int len, struct scatterlist *sg, int *sg_num_elem, unsigned int *sg_size, int first_coalesce) { struct page_frag *pfrag; unsigned int size = *sg_size; int num_elem = *sg_num_elem, use = 0, rc = 0; struct scatterlist *sge; unsigned int orig_offset; len -= size; pfrag = sk_page_frag(sk); while (len > 0) { if (!sk_page_frag_refill(sk, pfrag)) { rc = -ENOMEM; goto out; } use = min_t(int, len, pfrag->size - pfrag->offset); if (!sk_wmem_schedule(sk, use)) { rc = -ENOMEM; goto out; } sk_mem_charge(sk, use); size += use; orig_offset = pfrag->offset; pfrag->offset += use; sge = sg + num_elem - 1; if (num_elem > first_coalesce && sg_page(sg) == pfrag->page && sg->offset + sg->length == orig_offset) { sg->length += use; } else { sge++; sg_unmark_end(sge); sg_set_page(sge, pfrag->page, use, orig_offset); get_page(pfrag->page); ++num_elem; if (num_elem == MAX_SKB_FRAGS) { rc = -ENOSPC; break; } } len -= use; } goto out; out: *sg_size = size; *sg_num_elem = num_elem; return rc; }
int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb), void *from, int length, int transhdrlen, int hlimit, int tclass, struct ipv6_txoptions *opt, struct flowi6 *fl6, struct rt6_info *rt, unsigned int flags, int dontfrag) { struct inet_sock *inet = inet_sk(sk); struct ipv6_pinfo *np = inet6_sk(sk); struct inet_cork *cork; struct sk_buff *skb, *skb_prev = NULL; unsigned int maxfraglen, fragheaderlen, mtu; int exthdrlen; int dst_exthdrlen; int hh_len; int copy; int err; int offset = 0; __u8 tx_flags = 0; if (flags&MSG_PROBE) return 0; cork = &inet->cork.base; if (skb_queue_empty(&sk->sk_write_queue)) { /* * setup for corking */ if (opt) { if (WARN_ON(np->cork.opt)) return -EINVAL; np->cork.opt = kzalloc(opt->tot_len, sk->sk_allocation); if (unlikely(np->cork.opt == NULL)) return -ENOBUFS; np->cork.opt->tot_len = opt->tot_len; np->cork.opt->opt_flen = opt->opt_flen; np->cork.opt->opt_nflen = opt->opt_nflen; np->cork.opt->dst0opt = ip6_opt_dup(opt->dst0opt, sk->sk_allocation); if (opt->dst0opt && !np->cork.opt->dst0opt) return -ENOBUFS; np->cork.opt->dst1opt = ip6_opt_dup(opt->dst1opt, sk->sk_allocation); if (opt->dst1opt && !np->cork.opt->dst1opt) return -ENOBUFS; np->cork.opt->hopopt = ip6_opt_dup(opt->hopopt, sk->sk_allocation); if (opt->hopopt && !np->cork.opt->hopopt) return -ENOBUFS; np->cork.opt->srcrt = ip6_rthdr_dup(opt->srcrt, sk->sk_allocation); if (opt->srcrt && !np->cork.opt->srcrt) return -ENOBUFS; /* need source address above miyazawa*/ } dst_hold(&rt->dst); cork->dst = &rt->dst; inet->cork.fl.u.ip6 = *fl6; np->cork.hop_limit = hlimit; np->cork.tclass = tclass; if (rt->dst.flags & DST_XFRM_TUNNEL) mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ? rt->dst.dev->mtu : dst_mtu(&rt->dst); else mtu = np->pmtudisc == IPV6_PMTUDISC_PROBE ? rt->dst.dev->mtu : dst_mtu(rt->dst.path); if (np->frag_size < mtu) { if (np->frag_size) mtu = np->frag_size; } cork->fragsize = mtu; if (dst_allfrag(rt->dst.path)) cork->flags |= IPCORK_ALLFRAG; cork->length = 0; exthdrlen = (opt ? opt->opt_flen : 0); length += exthdrlen; transhdrlen += exthdrlen; dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len; } else { rt = (struct rt6_info *)cork->dst; fl6 = &inet->cork.fl.u.ip6; opt = np->cork.opt; transhdrlen = 0; exthdrlen = 0; dst_exthdrlen = 0; mtu = cork->fragsize; } hh_len = LL_RESERVED_SPACE(rt->dst.dev); fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + (opt ? opt->opt_nflen : 0); maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - sizeof(struct frag_hdr); if (mtu <= sizeof(struct ipv6hdr) + IPV6_MAXPLEN) { if (cork->length + length > sizeof(struct ipv6hdr) + IPV6_MAXPLEN - fragheaderlen) { ipv6_local_error(sk, EMSGSIZE, fl6, mtu-exthdrlen); return -EMSGSIZE; } } /* For UDP, check if TX timestamp is enabled */ if (sk->sk_type == SOCK_DGRAM) sock_tx_timestamp(sk, &tx_flags); /* * Let's try using as much space as possible. * Use MTU if total length of the message fits into the MTU. * Otherwise, we need to reserve fragment header and * fragment alignment (= 8-15 octects, in total). * * Note that we may need to "move" the data from the tail of * of the buffer to the new fragment when we split * the message. * * FIXME: It may be fragmented into multiple chunks * at once if non-fragmentable extension headers * are too large. * --yoshfuji */ if ((length > mtu) && dontfrag && (sk->sk_protocol == IPPROTO_UDP || sk->sk_protocol == IPPROTO_RAW)) { ipv6_local_rxpmtu(sk, fl6, mtu-exthdrlen); return -EMSGSIZE; } skb = skb_peek_tail(&sk->sk_write_queue); cork->length += length; if (((length > mtu) || (skb && skb_has_frags(skb))) && (sk->sk_protocol == IPPROTO_UDP) && (rt->dst.dev->features & NETIF_F_UFO)) { err = ip6_ufo_append_data(sk, getfrag, from, length, hh_len, fragheaderlen, transhdrlen, mtu, flags, rt); if (err) goto error; return 0; } if (!skb) goto alloc_new_skb; while (length > 0) { /* Check if the remaining data fits into current packet. */ copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; if (copy < length) copy = maxfraglen - skb->len; if (copy <= 0) { char *data; unsigned int datalen; unsigned int fraglen; unsigned int fraggap; unsigned int alloclen; alloc_new_skb: /* There's no room in the current skb */ if (skb) fraggap = skb->len - maxfraglen; else fraggap = 0; /* update mtu and maxfraglen if necessary */ if (skb == NULL || skb_prev == NULL) ip6_append_data_mtu(&mtu, &maxfraglen, fragheaderlen, skb, rt, np->pmtudisc == IPV6_PMTUDISC_PROBE); skb_prev = skb; /* * If remaining data exceeds the mtu, * we know we need more fragment(s). */ datalen = length + fraggap; if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len; if ((flags & MSG_MORE) && !(rt->dst.dev->features&NETIF_F_SG)) alloclen = mtu; else alloclen = datalen + fragheaderlen; alloclen += dst_exthdrlen; if (datalen != length + fraggap) { /* * this is not the last fragment, the trailer * space is regarded as data space. */ datalen += rt->dst.trailer_len; } alloclen += rt->dst.trailer_len; fraglen = datalen + fragheaderlen; /* * We just reserve space for fragment header. * Note: this may be overallocation if the message * (without MSG_MORE) fits into the MTU. */ alloclen += sizeof(struct frag_hdr); if (transhdrlen) { skb = sock_alloc_send_skb(sk, alloclen + hh_len, (flags & MSG_DONTWAIT), &err); } else { skb = NULL; if (atomic_read(&sk->sk_wmem_alloc) <= 2 * sk->sk_sndbuf) skb = sock_wmalloc(sk, alloclen + hh_len, 1, sk->sk_allocation); if (unlikely(skb == NULL)) err = -ENOBUFS; else { /* Only the initial fragment * is time stamped. */ tx_flags = 0; } } if (skb == NULL) goto error; /* * Fill in the control structures */ skb->ip_summed = CHECKSUM_NONE; skb->csum = 0; /* reserve for fragmentation and ipsec header */ skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + dst_exthdrlen); if (sk->sk_type == SOCK_DGRAM) skb_shinfo(skb)->tx_flags = tx_flags; /* * Find where to start putting bytes */ data = skb_put(skb, fraglen); skb_set_network_header(skb, exthdrlen); data += fragheaderlen; skb->transport_header = (skb->network_header + fragheaderlen); if (fraggap) { skb->csum = skb_copy_and_csum_bits( skb_prev, maxfraglen, data + transhdrlen, fraggap, 0); skb_prev->csum = csum_sub(skb_prev->csum, skb->csum); data += fraggap; pskb_trim_unique(skb_prev, maxfraglen); } copy = datalen - transhdrlen - fraggap; if (copy < 0) { err = -EINVAL; kfree_skb(skb); goto error; } else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { err = -EFAULT; kfree_skb(skb); goto error; } offset += copy; length -= datalen - fraggap; transhdrlen = 0; exthdrlen = 0; dst_exthdrlen = 0; /* * Put the packet on the pending queue */ __skb_queue_tail(&sk->sk_write_queue, skb); continue; } if (copy > length) copy = length; if (!(rt->dst.dev->features&NETIF_F_SG)) { unsigned int off; off = skb->len; if (getfrag(from, skb_put(skb, copy), offset, copy, off, skb) < 0) { __skb_trim(skb, off); err = -EFAULT; goto error; } } else { int i = skb_shinfo(skb)->nr_frags; struct page_frag *pfrag = sk_page_frag(sk); err = -ENOMEM; if (!sk_page_frag_refill(sk, pfrag)) goto error; if (!skb_can_coalesce(skb, i, pfrag->page, pfrag->offset)) { err = -EMSGSIZE; if (i == MAX_SKB_FRAGS) goto error; __skb_fill_page_desc(skb, i, pfrag->page, pfrag->offset, 0); skb_shinfo(skb)->nr_frags = ++i; get_page(pfrag->page); } copy = min_t(int, copy, pfrag->size - pfrag->offset); if (getfrag(from, page_address(pfrag->page) + pfrag->offset, offset, copy, skb->len, skb) < 0) goto error_efault; pfrag->offset += copy; skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); skb->len += copy; skb->data_len += copy; skb->truesize += copy; atomic_add(copy, &sk->sk_wmem_alloc); } offset += copy; length -= copy; } return 0; error_efault: err = -EFAULT; error: cork->length -= length; IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); return err; }